improve HTML menus, add social.html, prep for IOCCC28 winners

Prepare for the winners of **IOCCC28**.

> However these are not the 2024 droids you are looking for.  :-)

The HTML menu (both JavaScript and non-JavaScript) has been updated.

The `Status -> Rules and guidelines' have been replaced with two
separate menus `Status -> IOCCC rules` and `Status -> IOCCC guidelines`.

Added a new top level `social.html` page: built from a new `social.md`.

Sorted rules for building specific web pages in the top level `Makefile`.
Added `make social` to make the `social.html` page from `social.md`.

The `bin/gen-top-html.sh` now is able to process a argument of **social**
to process the new top level `social.html` page.

Changed `bin/gen-top-html.sh` VERSION from "2.0.0 2025-03-13"
to "2.0.1 2025-07-25".

Below `About -> Home page` a new `About -> IOCCC social media` menu item
as added.

Because the menu change touched every HTML file, we changed the general
copyright date range for HTML files from "1984-2024" to "1984-2025"
due to the extensive changes made for **IOCCC28**.

Those markdown files that were modified in 2025 had their copyright date
range also changed from "1984-2024" to "1984-2025".

Rebuilt tarballs and sitemap due to the extensive HTML rebuilding.

Ran `make update` to perform the above.

SECURITY.md

@@ -35,8 +35,9 @@ instead.
 # Important Disclaimer
 
 IOCCC code is for **educational and entertainment purposes only**. We do **NOT**
-recommend installing any winning IOCCC entry code. Use code found in the IOCCC repo
-and in the IOCCC website **at your own risk!**
+recommend installing any winning IOCCC entry code. Use code found in the
+[ioccc-src/winner GitHub repo](https://github.com/ioccc-src/winner)
+and in the [IOCCC website](index.html) **at your own risk!**
 
 The [IOCCC](index.html) and the [IOCCC judges](judges.html) DISCLAIM ALL
 WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF